ABSTRACT – This work develops and implements a novel topology aimed at enhancing the electric vehicle (EV) power factor at the front end of battery chargers. To eliminate the necessity for a diode-bridge-based converter in the EV battery charger, the proposed design utilizes a bridgeless power factor correction (PFC) converter. Battery charging is regulated in constant voltage and constant current modes by a dc–dc converter at the output of the proposed PFC converter. The proposed PFC converter uses a single sensing component, which ensures unity power factor at the input-side and stable dc load voltage, reducing device cost and complexity. The proposed topology achieves two crucial PFC criteria without the need for an inner loop or phase-locked loop, unlike the conventional PFC system. This topology has several advantages, including longer battery life, reduced device stress, improved power quality, fewer harmonics in the input current, and lower input/output current ripple. The simulation is to be carried out in MATLAB/Simulink software.
INTRODUCTION
The use of fossil fuels for electricity generation and heat from combustion engines continuously lead to a sharp increase in air pollution and global warming. The transportation sector is one of the major consumers of fossil fuels and produces mass-scale pollution. The rapid growth of population also demands higher consumption of electricity and indirect consumption of fossil fuels, degrading the quality of our environment day by day. Indian Government has taken many steps to reduce the carbon footprint and also aforesaid to be a zero-carbon-emission country by 2030, and with the plan, they use electrified railway service. Hence, there is a pressing demand for electrification in the transportation sector. An electric vehicle (EV) penetration of about 80% of light electric vehicles (LEVs) by 2030 in India is aimed. LEVs have faced growth limitations due to the absence of customer-oriented charging options. Currently available charging solutions do not adhere to established standards like IEC 61000-3-2 and IEEE 519, causing suboptimal charging efficiency with higher losses due to low power factors and excessive harmonics. The main source for EVs is rechargeable batteries, which are used to power EVs as per the load demands. These batteries are often charged with the help of an ac–dc converter, which is also termed an EV charger. Most EV chargers include a power factor correction (PFC) circuit at the input and then an isolated dc–dc converter in the next stage, which helps to provide constant current (CC) and constant voltage (CV) modes as per the state of charge (SOC) of the EV charger battery using various control techniques. The isolated converter is responsible for controlling the battery’s output current and voltage; thus, the charger’s performance also depends upon the isolated dc–dc converter’s performance while charging the battery. The concept of interleaving PFC is mentioned in the literature to reduce inductor size and improve harmonics; however, this can result in increased current stress on switches along with that several other full-bridge topologies possess benefits like high efficiency and high power density, but these suffer from high complexity. Another fascinating alternative is the use of an LLC resonant converter, which offers high power density and efficiency along with low electromagnetic interference (EMI) noise in the wide input range. However, an LLC converter suffers from very high complexity in design and analysis. Hence, such topologies are being replaced by ac–dc converters. This makes an ac–dc converter an integral part of the EV charger The literature describes the functionality of many diode bridge rectifier (DBR)-based topologies. These topologies have made the job simpler to achieve the desired requirements. However, such conventional chargers, as shown in Fig. 1, with the DBR at the front end cannot meet the required power quality standards due to the generation of large input-side harmonic distortion (about 55.3%), leading to a degraded source power factor. Such a low power factor, at the source end, creates a highly nonsinusoidal input current, which increases the displacement angle between the source current and voltage, and demands a large amount of reactive power from the source, which makes the system less efficient. Hence, there is a need to design an effective PFC scheme that excludes the severe effects of DBR in a traditional DBR-fed charger. The elimination of input-side DBR in the charger reduces system losses and improves efficiency. The literature discusses various bridgeless (BL) converter schemes based on dual boost configurations. The BL topology helps to lower the amount of current that is conducted via a smaller number of semiconductor components, which results in decreased losses and increased efficiency; this leads to reduced stress on switches and other components of the converter. This has further improved the converter’s overall performance and efficiency. The proposed converter is BL; thus, the source-side quantities also experience less power quality deterioration. Even though boost-converter-based BL topologies promise high efficiencies and an improved thermal stress level, they suffer from complicated control structures and high EMI noise. However, the boost converter has the limitation of change in duty cycle at low voltage to regulate the output voltage or dc-link voltage. Thus, a group of front-end BL boost topologies has been presented with a wide input range of voltage applications.

Block Diagram